Digest for sci.electronics.repair@googlegroups.com - 5 updates in 2 topics

tubeguy@myshop.com: Dec 11 01:08AM -0600

I was watching some youtube videos for restuffing electrolytics and wax
paper caps. I see no reason to do the wax paper ones, but I may try a
electrolytic can some day. But nowhere did they show anyone restuffing
the bumble bees. I dont plan to do it, but I'd like to see if its
possible. Those were some of the most colorful caps ever made, and those
would be the ones I'd want to preserve, if I had a lot of time to waste.
tabbypurr@gmail.com: Dec 11 02:25AM -0800

> the bumble bees. I dont plan to do it, but I'd like to see if its
> possible. Those were some of the most colorful caps ever made, and those
> would be the ones I'd want to preserve, if I had a lot of time to waste.
 
Sounds difficult. Repainting some old round plastic film caps might be easier, perhaps adding putty to get the right shape/size.
 
 
NT
John-Del <ohger1s@gmail.com>: Dec 11 04:44AM -0800

> the bumble bees. I dont plan to do it, but I'd like to see if its
> possible. Those were some of the most colorful caps ever made, and those
> would be the ones I'd want to preserve, if I had a lot of time to waste.
 
 
I will usually restuff a can electro just to keep things tidy, but I never understood the need to restuff leaded caps. I restored an Fender amp for a guy who wanted the wax caps restuffed, and he paid for the time. So..
 
I've never restuffed a Bumblebee, but maybe locking it down and boring with a small lathe will give adequate room without destroying the case. Capping it with black epoxy and shaping with a Dremel may give the look you want.
 
What ever floats your boat.
"pfjw@aol.com" <peterwieck33@gmail.com>: Dec 10 10:49AM -0800

OK - I am in an unique position here: I actually have worked with true 2-phase power, developed in the 1920s before 3-phase was well-established, as a means to provide off-set to start motors. Also pretty much confined to Philadelphia and Baltimore, being the two major cities in what became the PMJ Interconnect.
 
From PECO Tariffs:
 
Two-phase power is where the two phases are 90° apart.
 
This is a four (4) wire system, and the neutral currents do not cancel even if the system is in balance. Hence the need for four (4) wires.
 
I am surprised that so many went after the remark of audio and pacemakers. But here goes:
 
Pacemakers will accept all sorts of RF and other interference today - a vast improvement from the days when merely walking past a vintage microwave (in operation) would cause troubles.
 
But the modern pacemaker/defibrillators do not like stray currents in the body, as they may be taken as an event. If there is as much as a few volts difference between the NEUTRAL and the GROUND, and an individual so-equipped steps into that difference, that could be enough to trip the defib-function. Not (usually)fatal, but quite painful. Just ask the guy up on the 10th floor designing temporary artificial hearts - between restoring vintage Porsches. He will talk the paint off a board if given a chance - and I am sufficiently intrigued by what he does to give him those chances.
 
And, of course, there are hum-loops caused by stray currents.
 
Peter Wieck
Melrose Park, PA
Ralph Mowery <rmowery28146@earthlink.net>: Dec 10 04:30PM -0500

In article <2b63acc6-9213-497b-9eba-dfd2a61663e8@googlegroups.com>,
tabbypurr@gmail.com says...
> > running at 208 volts with a 120 instead of 180 phase shift across
> > the windings.
 
> Naturally some people don't understand some things, nothing new there.
 
Some do not understand that by definition and the way it is generated, 2
phase power is 90 deg out of phase, not 180.
 
There for in the US the common feed of 240 and 120 volts can not be 2
phase.
 
https://en.wikipedia.org/wiki/Two-phase_electric_power
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Digest for sci.electronics.repair@googlegroups.com - 25 updates in 9 topics

three_jeeps <jjhudak@gmail.com>: Dec 10 09:06AM -0800

On Saturday, December 8, 2018 at 11:43:27 PM UTC-5, Jeff Liebermann wrote:
> are also version with a "stiff" cable, which I've found quite useful.
> However, the apps all suck, the construction marginal, the Hi-Fi and
> BT versions are buggy, but for the price, all this can be tolerated.
 
I've used a few similar borescopes...the resolution of 640x480 is OK for seeing what is there but beyond that, fairly useless. The image distortion bothered me quite a bit as well.
Having said that, do you know of any produce with a higher resolution and better app?
Jeff Liebermann <jeffl@cruzio.com>: Dec 10 01:18PM -0800

On Mon, 10 Dec 2018 09:06:52 -0800 (PST), three_jeeps
>distortion bothered me quite a bit as well.
>Having said that, do you know of any produce with a higher resolution
>and better app?
 
Unfortunately, I'm going to have a high resolution endoscope used on a
very sensitive part of my anatomy tomorrow at the local surgery
center. I might ask the doctor for his favorite model, but suspect
he'll ignore me claiming that I'm drugged or delirious.
 
This looks fishy, but might be for real. 9mm dia (instead of the
usual 8mm) and 2megapixels in 1600x1200 with a 1/6th inch imager.
<https://www.newegg.com/Product/Product.aspx?Item=0XR-00BA-00024>
 
Compare with the real thing (for $4,000 and up):
<https://www.stryker.com/us/en/endoscopy.html>
<https://www.stryker.com/us/en/portfolios/medical-surgical-equipment/surgical-visualization.html>
 
I've found the Android and iPhone imaging software to be dismal or
worse. All that I've tried will crash with the slightest provocation.
Accidentally disconnecting the camera for even milliseconds often
requires a forced reboot. I have this bookmarked for later testing.
Might be worth trying:
<http://www.oasisscientific.com/downloads.html>
 
Incidentally, the best high resolution photos I've done were with a
commodity digital camera, junkbox optics, and a commercial endoscope.
I make the adapter out of plastic plumbing parts turned down to size
on my drill press. Ugly, but amazingly useful. Something bolted onto
a smartphone might produce decent results:
<https://www.endoscope-i.com>
 
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
bitrex <user@example.net>: Dec 03 09:27PM -0500

On 12/03/2018 09:05 PM, Clifford Heath wrote:
> and solder the other side. Make sure the track has wettable surfaces
> exposed first, or course.
 
> Clifford Heath.
 
Thanks, will try. Even with magnification, smallest tip I have and a Zen
meditation session beforehand I'm not sure I'm precise enough to pull
this off but I'll take a shot at it
Look165 <look165@numericable.fr>: Dec 04 11:44AM +0100

CircuitWorks provide conductive ink pens.
 
From my own experience, try first on something else.
 
bitrex a écrit :
bitrex <user@example.net>: Dec 03 08:53PM -0500

Due to an unfortuante jab with the head of a screwdriver it looks like I
have at least one, possibly two broken traces on this GPU card, on the
traces running between the processor and VRAM. Result is corrupted
display output/won't switch into high-resolution modes. The ram is BGA
and the GPU likewise and under a small heat-sink so hard to test
continuity, plus the trace width is very small, looks like perhaps 4 mil:
 
<https://www.dropbox.com/s/ig9h3vjze5omlie/2018-12-3%2018-11-20.jpg?dl=0>
 
Palette inverted:
 
<https://www.dropbox.com/s/m05pikt3yexq2f6/2018-12-3%2018-11-30.jpg?dl=0>
 
Any suggestions for mending a break on a trace like this?
Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Dec 04 03:59AM +0100

On 4-12-2018 3:05, Clifford Heath wrote:
> and solder the other side. Make sure the track has wettable surfaces
> exposed first, or course.
 
> Clifford Heath.
 
+20
Clifford Heath <no.spam@please.net>: Dec 04 01:05PM +1100

On 4/12/18 12:53 pm, bitrex wrote:
 
> Palette inverted:
 
> <https://www.dropbox.com/s/m05pikt3yexq2f6/2018-12-3%2018-11-30.jpg?dl=0>
 
> Any suggestions for mending a break on a trace like this?
 
Fine wire. Pre-tin it, solder to one side of the break, pull straight
and solder the other side. Make sure the track has wettable surfaces
exposed first, or course.
 
Clifford Heath.
N_Cook <diverse@tcp.co.uk>: Dec 04 08:34AM

On 04/12/2018 01:53, bitrex wrote:
 
> Palette inverted:
 
> <https://www.dropbox.com/s/m05pikt3yexq2f6/2018-12-3%2018-11-30.jpg?dl=0>
 
> Any suggestions for mending a break on a trace like this?
 
Assuming only light currents. Lightly abraid in that area , to enough
bare traces, cover with silver-loaded paint. When perfectly dry, score
parallel lines with a scalpel blade . Check for any bridging before
perhaps coating with lacquer
dplatt@coop.radagast.org (Dave Platt): Dec 03 05:15PM -0800

In article <v6ib0eprmjiaikh9i355ns2tiqvirgk07q@4ax.com>,
> A parameter who's function is not listed in the book so I
>didn't know what it did. But I had written down all the parameters
>when I bought the machine
 
Very wise!
 
> All I did was change a 0 back to a 1. I wonder how the damn
>parameter changed in the first place?
 
Might have been a bit flip in memory somewhere (cosmic ray, bad IC,
etc.).
 
Or, is possible to change those parameters under software control that
doesn't require the manual "parameter unlock" switch? A garbled
command sent to the device - even a one-character error in
transmission - might have "silently" changed a parameter in an
unexpected way.
 
Or, maybe, this parameter was changed as a side-effect of some other
(legal and reasonable) command?
etpm@whidbey.com: Dec 03 04:41PM -0800

I live on an island and it is hard to get CNC repair people out to
look at the machines. So I fix 'em myself.
The Miyano lathe developed a problem last week. It refused to
execute one particular M code, the spindle speed could no longer be
controlled in a program, the jog spindle speed dial now controlled
speed even in auto mode when it should not, and the "used up" alarm
came on after every part.
I called FANUC and they figured it was a particular circuit board.
I found one on eBay and ordered it. But it's a week and a half away.
I checked all the diagnostic parameters and everthing was fine.
Then this afternoon I checked the regular parameters and one had
changed. A parameter who's function is not listed in the book so I
didn't know what it did. But I had written down all the parameters
when I bought the machine, they are mostly 8 digits long, just ones
and zeros, but some are otherwise, such as backlash amounts, which are
entered as some multiple of one ten thousandth of an inch. The machine
was used when I bought it so some of the original parameters could
have changed, like backlash. And I have changed parameters too in
order to get the machine to do things it did not do when I bought it.
So I got into the back of the machine, where all the high voltage
is, along with the computer, opened up the computer enclosure and
flipped the parameter change switch. Then I used the control keyboard
to change the parameter back to where it was, got back behind the
lathe and flipped the parameter switch, cleared the alarm that happens
whenever a parameter is changed, and the machine now works great.
All I did was change a 0 back to a 1. I wonder how the damn
parameter changed in the first place?
Anyway, I am really happy now. Really happy. I mean REALLY HAPPY!
Eric
etpm@whidbey.com: Dec 03 05:35PM -0800

On Mon, 3 Dec 2018 17:15:36 -0800, dplatt@coop.radagast.org (Dave
Platt) wrote:
 
>unexpected way.
 
>Or, maybe, this parameter was changed as a side-effect of some other
>(legal and reasonable) command?
As far as I know there is no way, oiher than flipping the parameter
switch, to change parameters. And besides, it worked one day and then
whenturned on the next day did not.
Eric
etpm@whidbey.com: Dec 04 09:15AM -0800

On Mon, 3 Dec 2018 23:21:10 -0500, Ralph Mowery
>a year or so.
 
>When memory chips first came out, it was said that the coverings of them
>might emit an alpha partical and flip a bit.
I figure it was a cosmic ray. Maybe my machine has a nuetrino detector
in it! 1 detection in many years fits the bill. How many years I don't
know but the machine has been around a long time. I could wrap the
machine in lead to protect it but I don't have any two light years
thick pieces.
Eric
etpm@whidbey.com: Dec 03 05:39PM -0800

On Mon, 3 Dec 2018 17:17:18 -0800, John Robertson <spam@flippers.com>
wrote:
 
>(batter or propane is easiest) if it requires unsoldering. Extend the
>wiring to it so it is away from any electronics...
 
>John :-#)#
The machine does have battery backup. An alarm condition tells you
when it is time to replace batteries. FANUC controls are very good at
telling you when it is time to change batteries. Nevertheless I always
change batteries on a schedule so the alarm has only happened once,
shortly after I bought the machine.
Eric
Lucifer <LuciferMorningstar@bigpond.com>: Dec 02 10:35PM +1100

On Sun, 2 Dec 2018 01:31:27 -0600, Fox's Mercantile <jdangus@att.net>
wrote:
 
>> off yet but I'm thinking the VFO variable capacitor is being
>> prevented from full movement.
 
>There isn't a VFO capacitor. The radio uses phase locked loops.
 
Thank you for your reply and the manual links, however you are
wrong about the VFO capacitor.
It uses the PLL to select the band and the VFO to tune within the
band. The Kenwood R-1000 works the same way.
 
Tim Schwartz <tim@bristolnj.com>: Dec 03 03:21PM -0500

Hi there,
 
CTS (Chicago Telephone Supply) is a different company. You can find a
company history, in annoying reverse order, so you have to scoll from
the bottom up, here:
 
https://www.ctscorp.com/company/history/
 
Regards,
Tim
 
 
On 12/3/2018 8:12 AM, John-Del wrote:
Tim Schwartz <tim@bristolnj.com>: Dec 03 03:23PM -0500

Hi there,
 
CTS (Chicago Telephone Supply) is a different company. You can find a
company history, in annoying reverse order, so you have to scroll from
the bottom up, here:
 
https://www.ctscorp.com/company/history/
 
Regards,
Tim
 
 
On 12/3/2018 8:12 AM, John-Del wrote:
etpm@whidbey.com: Dec 03 09:15AM -0800

On Sun, 2 Dec 2018 19:38:33 -0500, Tom Biasi <tombiasi@optonline.net>
wrote:
 
>> Eric
 
>I'm just curious as to what product has that spec. 110 VAC on an old
>amplifier means line voltage in North America. The 5% is odd to me.
Nobsound. Who knows why the spec but I don't want to burn up expensive
tubes prematurely.
Eric
Tom Biasi <tombiasi@optonline.net>: Dec 03 12:49PM -0500

> Nobsound. Who knows why the spec but I don't want to burn up expensive
> tubes prematurely.
> Eric
 
Do you have a model number?
Michael Black <mblack@pubnix.net>: Dec 03 02:34PM -0500

On Sun, 2 Dec 2018, The Real Bev wrote:
 
> before asking. The problem is crud between the screen and the frame.
> Carefully drag the corner of a piece of ordinary paper under the edge all the
> way around. Yeah, I was suspicious too, but it worked!
 
That's interesting, I wonder what other devices might suffer in the same
way?
 
I got a TomTom One GPS for ten dollars at a rummage sale, and the touch
aspect seemed flakey initially, but after charging and some use, all seems
fine. I got a PDA last year, and the touch screen (you needed a stylus)
seems unrepsonsive, I was wondering what might be involved, not that it
really matters, it was a few dollars and I have no real use for one.
 
Michael
The Real Bev <bashley101@gmail.com>: Dec 03 12:07PM -0800

On 12/03/2018 11:34 AM, Michael Black wrote:
> fine. I got a PDA last year, and the touch screen (you needed a stylus)
> seems unrepsonsive, I was wondering what might be involved, not that it
> really matters, it was a few dollars and I have no real use for one.
 
So haul it out and try it. Surely you didn't throw it away...
 
How do the edges know which spot on the screen was touched? Was the bit
of crud in ONE specific place that somehow allowed the whole thing to
work, like a ground connection or something? Is the whole thing like a
required ground connection and a bit of crud somehow breaks that
connection? The website guy used paper; what if I'd used a tiny bit of
toothpick sliver or wire or plastic?
 
I have an older Lenovo laptop with a touchscreen that I rarely use; it
must have a frame. If it ever goes wonky I'll try it.
 
--
Cheers, Bev
I'd rather not have neighbors. If I can see them, they're too close.
In fact, if I can see them through a rifle scope, they're too close.
-- Anonymous Coward
burfordTjustice <burfordTjustice@tues.uk>: Dec 04 10:08AM +0100

Post in violation of terms-of-service cancelled by Sir Cancelot <cancelbot@eternal-september.org>
From: burfordTjustice <burfordTjustice@tues.uk>
Subject: Re: WD-40 to clean electric contacts?
Message-ID: <oe85dn$6fb$3@dont-email.me>
Newsgroups: alt.home.repair,sci.electronics.repair
"BurfordTJustice" <burford/associate@uk.MI15>: Dec 04 10:42AM +0100

Post in violation of terms-of-service cancelled by Sir Cancelot <cancelbot@eternal-september.org>
From: "BurfordTJustice" <burford/associate@uk.MI15>
Subject: Re: Why won't this work?
Message-ID: <pad7e7$hhr$1@dont-email.me>
Newsgroups: sci.electronics.repair,alt.home.repair
whit3rd <whit3rd@gmail.com>: Dec 10 05:08PM -0800

On Sunday, December 9, 2018 at 9:02:42 AM UTC-8, Ron D. wrote:
> > I had an EICO FET TVM. I still have it. ...
> > I doubt the cabeling matters and RG-58 would probably suffice.
 
> You can get RG174 and other cable by th foot. e.g. https://www.showmecables.com/bulk-rg174-coaxial-cable-26-awg-per-ft
 
The center conductor on RG174 is flimsy, RG-58 or RG-59 are somewhat more
mechanically robust (but the insulation will have to be replaced, or spliced to a few inches
of more flexible wire). For any non-RF work, microphone cable (shielded pair) might
also be useful.
Fox's Mercantile <jdangus@att.net>: Dec 10 10:58AM -0600

>> the ± nature of it.
>> It is not, the primary is single phase.
 
> 3 phase has an angle between each phase of 360/3 = 120 degrees.
 
Correct.
 
> 2 phase has an angle between each phase of 360/2 = 180 degrees.
> And that's what you have with the US domestic 120/240 system.
 
Absolutely NOT. That is center tapped single phase.
In the early days of electrical generation, there was 2-phase, but the
two phases were offset by 90 degrees.
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
tabbypurr@gmail.com: Dec 10 09:06AM -0800

On Monday, 10 December 2018 16:58:22 UTC, Fox's Mercantile wrote:
 
> > 2 phase has an angle between each phase of 360/2 = 180 degrees.
> > And that's what you have with the US domestic 120/240 system.
 
> Absolutely NOT. That is center tapped single phase.
 
It's one of the 3 phase distribution system's phases, centre tapped, that is its source. That does not change the fact that it's 2 phase.
 
> In the early days of electrical generation, there was 2-phase, but the
> two phases were offset by 90 degrees.
 
I've read various times of 2 phase systems with 180 degree offset, but not seen 90 degrees.
 
 
NT
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Digest for sci.electronics.repair@googlegroups.com - 17 updates in 4 topics

"Ron D." <ron.dozier@gmail.com>: Dec 09 11:14AM -0800

> t.....r@gmail.com says...
 
> > All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.
 
Nope:
 
The neutral carries the "difference current" in the legs of a split phase system. It can be 180 or -180 out of phase (Said for ease of understanding). It can also be zero, but not likely,
 
The "difference current" is more accurate. While voltage is usually sinusoidal, current doesn't have to be. Voltage is what's regulated. inductive loads are one matter, but laptop switching power supplies is another.
Phil Allison <pallison49@gmail.com>: Dec 09 12:24PM -0800

Ron D. wrote:
 
 
> > > All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going.
 
> Nope:
 
** Fraid it is a yep.
 
Any mains appliance returns the same current down the neutral conductor it drew from the active. This mean very little mag field is generated by the appliance's own lead, assuming the two wires are closely paired or twisted.
 
 
 
... Phil
Ralph Mowery <rmowery28146@earthlink.net>: Dec 09 04:14PM -0500

In article <137d918d-cb77-4a4f-989b-66c8d7dbe141@googlegroups.com>,
pallison49@gmail.com says...
 
> ** Fraid it is a yep.
 
> Any mains appliance returns the same current down the neutral conductor it drew from the active. This mean very little mag field is generated by the appliance's own lead, assuming the two wires are closely paired or twisted.
 
I think you all are compairing apples and oranges.
 
One is thinking of a 240 volt system with 2 hots and the neutral, whrere
the neutral can have almost any ammount of current on it up to being
equal to what one side of the hot is using (120 volt devices).
 
Phil and the other are probably talking about a 120 volt device that has
only a hot and neutral. Which in that case the neutral must have the
same ammount of cuttent as the hot wire, unless there is a problem.
Fox's Mercantile <jdangus@att.net>: Dec 09 04:19PM -0600

On 12/9/18 3:14 PM, Ralph Mowery wrote:
> One is thinking of a 240 volt system with 2 hots and the neutral, whrere
> the neutral can have almost any ammount of current on it up to being
> equal to what one side of the hot is using (120 volt devices).
 
This is one of fallacies here in Ranger.
Around here, the thought is the Neutral to the breaker panel from
the meter can be smaller because it's not going to carry ALL of the
current because there will be an offsetting current from the other
hot leg.
 
They also tend to under size everything, because, you know, copper
is expensive. For example, my house has a 200 Amp service.
That should be #000 on all three legs and #4 for the ground.
When I got here, it was two #4 on the hots, #6 on the neutral and
#10 for the ground.
That was one of the first things I fixed.
 
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Ralph Mowery <rmowery28146@earthlink.net>: Dec 09 05:50PM -0500

In article <DMqdnZNXDrKSCJDBnZ2dnUU7-I3NnZ2d@giganews.com>,
jdangus@att.net says...
> When I got here, it was two #4 on the hots, #6 on the neutral and
> #10 for the ground.
> That was one of the first things I fixed.
 
Well you do not have to worry about ice forming on the power wires. I
think one chart showed about 105 deg C for the temperature rise with the
# 4 wire at around 200 amps.
Clifford Heath <no.spam@please.net>: Dec 10 12:33PM +1100

On 10/12/18 8:14 am, Ralph Mowery wrote:
 
> Phil and the other are probably talking about a 120 volt device that has
> only a hot and neutral. Which in that case the neutral must have the
> same ammount of cuttent as the hot wire, unless there is a problem.
 
Phil lives in Sydney. We use 240V single phase wiring, with a single hot
and a single neutral grounded at the panel. The RCD protection trips if
the currents on hot and neutral differ, even by milliamps for milliseconds.
 
Some (few) buildings have two separate 240V phases wired to different
circuits inside the house, but nothing gets connected between the phases.
 
Clifford Heath.
Phil Allison <pallison49@gmail.com>: Dec 09 07:30PM -0800

Ralph Mowery wrote:
 
 
> One is thinking of a 240 volt system with 2 hots and the neutral, whrere
> the neutral can have almost any ammount of current on it up to being
> equal to what one side of the hot is using (120 volt devices).
 
** If a 240V load is connected across the two phases, then the current is each wire is the same.
 
The principle is simple: a current carrying loop that is closed down on itself ( ie the wires are paralleled) or twisted cannot radiate a mag field.
 
 
.... Phil
tabbypurr@gmail.com: Dec 10 02:04AM -0800

On Sunday, 9 December 2018 19:14:44 UTC, Ron D. wrote:
 
> Nope:
 
> The neutral carries the "difference current" in the legs of a split phase system. It can be 180 or -180 out of phase (Said for ease of understanding). It can also be zero, but not likely,
 
> The "difference current" is more accurate. While voltage is usually sinusoidal, current doesn't have to be. Voltage is what's regulated. inductive loads are one matter, but laptop switching power supplies is another.
 
 
I think you'll find house sockets are wired single phase.
 
 
NT
Fox's Mercantile <jdangus@att.net>: Dec 10 05:42AM -0600


> I think you'll find house sockets are wired single phase.
 
> NT
 
Actually, the term "Split Phase" is accurate.
The source is a center tapped 240 volt winding.
-180 0 +180 degrees.
Either side to center (neutral) is 120v, and across both sides (hot)
is 240v.
The usual problem is when people insist on calling it 2-phase due to
the +/- nature of it.
It is not, the primary is single phase.
 
The real problem occurs in a 3-phase Wye system.
A-N, B-N and C-N are each 120 volts. Until someone who doesn't know
how it works, takes A-B and tells the consumer it's 240v. And then
typically table saws go up in flames, because they REALLY do no like
running at 208 volts with a 120 instead of 180 phase shift across
the windings.
 
 
 
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Look165 <look165@numericable.fr>: Dec 10 01:01PM +0100

120*(3^^0.5) gives 207V, not 240.
 
Fox's Mercantile a écrit :
tabbypurr@gmail.com: Dec 10 04:22AM -0800

On Monday, 10 December 2018 11:42:17 UTC, Fox's Mercantile wrote:
> The usual problem is when people insist on calling it 2-phase due to
> the +/- nature of it.
> It is not, the primary is single phase.
 
3 phase has an angle between each phase of 360/3 = 120 degrees.
2 phase has an angle between each phase of 360/2 = 180 degrees. And that's what you have with the US domestic 120/240 system.
 
 
> typically table saws go up in flames, because they REALLY do no like
> running at 208 volts with a 120 instead of 180 phase shift across
> the windings.
 
Naturally some people don't understand some things, nothing new there.
 
 
NT
Fox's Mercantile <jdangus@att.net>: Dec 10 06:26AM -0600

On 12/10/18 6:01 AM, Look165 wrote:
> 120*(3^^0.5) gives 207V, not 240.
 
207.84 or commonly called 208.
 
I said uneducated electricians THINK that two 120v phases
running 120 degrees instead of 180 degrees apart equals
240 volts.
 
As a service manager in a tool store, I had to explain that
running a 5 HP table saw motor on 208 volts was NOT covered
under warranty and they should make their "electrician" pay
for the repairs.
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
MOP CAP <email@domain.com>: Dec 09 05:13PM -0800

In a selenium rectifier the big plates are BOTH rectifiers and heat sinks!
Seen the hugh vacuum chambers in which the were made.
CP
tabbypurr@gmail.com: Dec 10 02:02AM -0800

> >are extremely fussy about that.
 
> I plan to leave it on the chassis for looks, but replace it.
> My voltage is real low, so it seems it's weak or worse....
 
and about to go into toxic fumes mode.
Jeff Liebermann <jeffl@cruzio.com>: Dec 09 11:37AM -0800

On Sun, 9 Dec 2018 10:14:11 -0500, Ralph Mowery
>I am not that much of a touch typist. I can do the letters and a few
>common punctuations,but have to look for some of the other symbles. I
>never look at the mouse once I find it and get it in my hand.
 
Thanks for the info. It's about the same for me. The common
characters I can type without looking. The shifted characters require
my looking at the keyboard.
 
>lenses come with it. Mine came with a 10x and 20x lense. I almost
>always use the 10x lense. I bought a 5x but found the one i got did
>not seem to have a large a field of view as the 10x.
 
I rather prefer adjustable power in the head (0.7x to 3x) as in the
Bausch and Lomb scopes. I have a variety of eyepieces but WF10X is
what works best for PCB work.
 
>I don't have any problem at all looking through the scope and working.
>AT 68 I do not seem to have any major problems with the shakes.
 
I'm at 70. No shakes. However, I do have some problems adjusting to
working under the microscope or HUD. I probably need more practice.
 
>rework station from China that has the hot air wand and soldering
>pencil. If I was using the equipment to make money,I would get something
>better.
 
I have the bad habit of buying used test equipment and tools. None of
my microscopes were purchased new. A few of my objective lenses and
eyepieces were purchased new, but most came with the used scopes. If
I were still doing this professionally, I would not have time to do
the necessary repairs on the used equipment and probably would have
bought something that was ready to use.
 
>There is a fellow on youtube (Louis Rossman) that works on Apple
>computers and at one time he was pushing that scope for the price.
 
"Amscope SE400-z microscope, a must have tool for repair technicians."
<https://www.youtube.com/watch?v=m4LaZsS5V7s> (7:45)
 
>have any use for the camera. His newer scopes have a way of mounting
>the camera where he can still see through both lenses and a 3 rd lense
>for the camera.
 
In the above video, he uses his Android phone through one eyepiece. He
has some other scopes, one of which is a trinocular microscope, which
has a third tube for the camera (but less working range).
 
For photos, I have one of these:
<https://www.amscope.com/cameras/0-3-mega-pixel-usb-live-video-microscope-imager-digital-camera.html>
I should have bought one with a 0.5x lens, but decided to go cheap.
Big mistake because the image width is about half the width as viewed
through the eyepiece.
 
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
"Ron D." <ron.dozier@gmail.com>: Dec 09 09:00AM -0800

I had an EICO FET TVM. I still have it. D Cell for the ohmeter and a 9V battery for the voltmeter.
 
Mine had the phone plug as yours does and also. The probe was quite large in diameter and could turn to insert/remove the resistor (whatever value it was).
 
I think it was AC/Ohms and DC,
 
I doubt the cabeling matters and RG-58 would probably suffice.
 
If you keep your voltages down, RG174 is about 1/2 the diameter (0.1") of RG-58
 
RG58/59; http://www.scp-sa.es/resources/upload/files/categorias/148/esp/RG58_RG59.pdf
 
RG59 is TV stuff with a solid core.
 
RG174 https://www.awcwire.com/productspec.aspx?id=rg174-coaxial-cable is good for 1500 VRMS and it quite flexible.
 
If had to actually make a probe and it made a difference as to whether the resistor is in the tip or the plug, You can get a BNC for the probe end.
 
But then some of the standard probes could likely easily accommodate a series resistor inside. Especially some of the adjustable probes like these: https://www.fluke.com/en-us/product/accessories/test-leads/fluke-tl40
"Ron D." <ron.dozier@gmail.com>: Dec 09 09:02AM -0800

On Sunday, December 9, 2018 at 12:00:36 PM UTC-5, Ron D. wrote:
 
> RG174 https://www.awcwire.com/productspec.aspx?id=rg174-coaxial-cable is good for 1500 VRMS and it quite flexible.
 
> If had to actually make a probe and it made a difference as to whether the resistor is in the tip or the plug, You can get a BNC for the probe end.
 
> But then some of the standard probes could likely easily accommodate a series resistor inside. Especially some of the adjustable probes like these: https://www.fluke.com/en-us/product/accessories/test-leads/fluke-tl40
 
You can get RG174 and other cable by th foot. e.g. https://www.showmecables.com/bulk-rg174-coaxial-cable-26-awg-per-ft
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